Filling agent

ABSTRACT

The use of amylopectin-type starch obtained from potato that has been modified by genetic engineering to suppress the formation of amylose-type starch as a filling agent in the preservation of food-stuff, is described.

The present invention relates to the use of amylopectin-type starch orderivatives thereof as a filling agent in the preservation offood-stuffs.

More precisely, the present invention relates to the use ofamylopectin-type starch obtained from potato that has been modified bygenetical engineering, to suppress the formation of amylose-type starch.

BACKGROUND OF THE INVENTION

In the process of autoclaving and sterilisation of food-stuff containingsolid pieces, a certain filling viscosity is required while the tin isbeing filled and conveyed on the belt conveyor, since it has been foundthat the liquid fraction of the tin contents easily splashes over thetin rim. Another reason for a certain viscosity being desirable in theproduct is that it furthers an equal distribution of the solid pieces inthe food-stuff mass. This feature is also important as productscontaining solid pieces are sterilised in a continuous process, forinstance in the case of soups, which are packed in an aseptic conditionin the final packaging stage. Considering that the mass to be preservedoften is in a hot condition during the filling stage, the operatorsconcerned are exposed to scalding hazards from splash and slosh if theproduct is too thin during this stage.

Earlier on, this problem was solved by addition of traditional starchbut the results were not satisfactory, because it produced an unwantedresidual viscosity in the tin. Previously, naturally occurring potatoflour, naturally occurring waxy maize starch, and waxy maize starch towhich isoascorbic acid or ascorbic acid had been added (to eliminate theresidual viscosity in naturally occurring maize starch) were used withinthe canned goods industry to obtain the desired function. However, ithas been found that none of these additions produced a satisfactoryresult. Naturally occurring potato flour produces residual viscosity andclouding, for instance during storage of clear liquids such as brine, inpreserved vegetables, but also causes the product to thicken duringstorage. Naturally occurring waxy maize starch produces a certainresidual viscosity but also some clouding of the solution. Although theaddition of isoascorbic acid or ascorbic acid increases the clearness ofthe product, residual viscosity is generated to varying degrees as theacids are degraded by organic matter originating from other ingredientsin the preserved product. Thus, problems arise in connection with thepreservation, both on account of the undesired residual viscosity and ofthe clouding of the product, and it is desired within the canned goodsindustry that these problems be removed.

OBJECT OF THE INVENTION

The object of the present invention is to eliminate the above-mentionedproblems and provide a preservation method ensuring low residualviscosity and clearness in the product. This object is achieved by usingamylopectin-type starch of the kind defined in the introduction, whichstarch additionally possesses the characteristics defined in theappended claims.

SUMMARY OF THE INVENTION

In accordance with the present invention amylopectin-type of starch orderivatives thereof thus is used as a filling agent in the preservationof food-stuff.

The expression "amylopectin-type starch" as used throughout in thepresent description relates to starch obtained from potato that has beenmodified by genetical engineering to suppress the formation ofamylose-type starch. The expression "derivatives thereof" relates toamylopectin-type starch that has been chemically, physically and/orenzymatically derivatised. The amylopectin contents of amylopectin-typestarch are in excess of 95%, preferably in excess of 98%. The remainingingredient in amylopectin-type starch is amylose.

For a detailed description of the above amylopectin-type starch andderivatives thereof and the manner in which they are produced referenceis made to the Swedish Patent Specification 9004096-5 (Amylogene HB).

Naturally occurring potato starch contains about 80% amylopectin andabout 20% amylose. The starch is contained in small grains, alsodenominated granules. When water and heat are added, the granules swell,with the result that the viscosity increases and amylose leaks from thegranules. When the amylose contents in the starch have been reduced to alow level, the starch granule becomes very fragile and easily breakswhen boiled. This means that amylopectin-type starch used as a fillingagent in the initial filling and conveyor transportation of the tinpossesses a sufficiently high degree of viscosity to meet therequirements at this stage of the preservation process, but that as aresult of the subsequent heat treatment this viscosity drops to adesired residual viscosity level upon completion of the process cycle.This means that no supplementary addition of viscosity-reducing acidsneed to be made, which otherwise is common practise. Sincepotato-derived starch has very low contents of residual protein andresidual fat, there is not either any tendencies of cloudiness, whichwould otherwise be the case, were for instance waxy maize starch to beused. The reason therefor is the extremely low contents of amylose inamylopectin-type starch. Otherwise, the cloudiness is related to theinstability of amylose in solution.

By using amylopectin-type starch as a filling agent in the preservationof food-stuff the earlier encountered problem with too high residualviscosity levels and cloudy products thus has been eliminated. A furtheradvantage offered by the present invention is the prolongation of thestorage life of the preserved product.

The example below aims at describing the present invention in moredetail.

EXAMPLE

A liquid to be preserved is heated to 70°-80° C. The amylopectin-typestarch used as a filling agent is formed into a slurry in twice theamount by weight of a cold liquid, such as water, whereafter it wasadmixed with the heated liquid while being stirred. After a brief periodof time the starch has swelled and the desired viscosity is attained.The preparation is then ready to serve as a filling agent or to besubjected to further processing. To attain the desired viscosity adosage of 0.5-3.5% by weight of the amylopectin-type starch, calculatedon the total amount of liquid, is required. Upon continued maintenanceof the temperature level, the amylopectin readily degrades, leading todecreasing viscosity. In this manner, a desired low level of residualviscosity is obtained in the product.

It is not previously known to use amylopectin-type starch as definedabove as a filling agent in the preservation of food-stuff, andpractical tests have shown the surprising combined effects of reducedresidual viscosity, increased clearness in the product, and prolongedstorage life.

I claim:
 1. A method of processing a food-stuff comprising the stepsof:adding amylopectin-type starch obtained from a genetically modifiedpotato to the food-stuff.
 2. The method of claim 1 wherein theamylopectin-type starch contains more than 95% amylopectin.
 3. Themethod of claim 1 wherein the amylopectin-type starch contains more than98% amylopectin.
 4. The method of claim 1 wherein the amylopectin-typestarch has been chemically, physically or enzymatically derivatized. 5.The method of claim 1 wherein the amylopectin-type starch is added in anamount of 0.5-3.5% by weight.
 6. The method of claim 3 wherein theamylopectin-type starch is added in an amount of 0.5-3.5% by weight. 7.The method of claim 4 wherein the amylopectin-type starch is added in anamount of 0.5-3.5% by weight.
 8. A method of controlling the viscosityof a food-stuff comprising the steps of:adding amylopectin-type starchobtained from a genetically modified potato to the food-stuff, andoptionally heating the food-stuff to obtain a desired residualviscosity.
 9. The method of claim 8 wherein the amylopectin-type starchcontains more than 95% amylopectin.
 10. The method of claim 8 whereinthe amylopectin-type starch contains more than 98% amylopectin.
 11. Themethod of claim 8 wherein the amylopectin-type starch has beenchemically, physically or enzymatically derivatized.
 12. The method ofclaim 8 wherein the amylopectin-type starch is added in an amount of0.5-3.5% by weight.
 13. The method of claim 10 wherein theamylopectin-type starch is added in an amount of 0.5-3.5% by weight. 14.The method of claim 11 wherein the amylopectin-type starch is added inan amount of 0.5-3.5% by weight.
 15. A method of preserving a food-stuffcomprising the steps of:adding amylopectin-type starch obtained from agenetically modified potato to the food-stuff, and heating thefood-stuff.
 16. The method of claim 15 wherein the amylopectin-typestarch contains more than 95% amylopectin.
 17. The method of claim 15wherein the amylopectin-type starch contains more than 98% amylopectin.18. The method of claim 15 wherein the amylopectin-type starch has beenchemically, physically or enzymatically derivatized.
 19. The method ofclaim 15 wherein the amylopectin-type starch is added in an amount of0.5-3.5% by weight.
 20. The method of claim 18 wherein theamylopectin-type starch is added in an amount of 0.5-3.5% by weight.